Trunking audio distortion

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K3WSU

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I have BCD536HP and have a single system ICORRS P25 APCO programmed and only scanning one county. I have plenty of signal. Certain feeds are garbled or choppy and cut out. Since it's a trunking system, I can't adjust any of the P25 settings. I have tried turning on and off the digital AGC and leaving it off has some improvement. I have a 996XT that decodes correctly. Is there any way the P25 settings can be adjusted in trunking mode ? It seems like the threshold isn't correct...Any suggestions will be greatly appreciated... thanks in advance..
 

goodmore

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As I was told I will tell you. There is no quick fix. The two most popular answers are to play with the threshold setting, and get a directional antenna. The threshold can be adjusted by going in to the adjust site setting. Watch your error rate and try to keep it low. You can see it pop up during a hit on the channel. The bad news is you have to navigate the menu every time you want to make a change. The error rate can be seen by pushing function/volume. Top line of the scanner.
 

ofd8001

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You can change the settings. Use Sentinel to edit the Favorites List containing the system. Click on the site and look for the Options tab in the right pane and open it.

The settings you can change are:

Attenuator Off or On
Digital Threshold Mode Auto/Manual/Default
Threshold Level 5 - 13

You will have to try a variety of combinations to find the "sweet spot" of least garble. It will probably take several attempts, so be patient.
 

mitbr

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I have BCD536HP and have a single system ICORRS P25 APCO programmed and only scanning one county. I have plenty of signal. Certain feeds are garbled or choppy and cut out. Since it's a trunking system, I can't adjust any of the P25 settings. I have tried turning on and off the digital AGC and leaving it off has some improvement. I have a 996XT that decodes correctly. Is there any way the P25 settings can be adjusted in trunking mode ? It seems like the threshold isn't correct...Any suggestions will be greatly appreciated... thanks in advance..

This is VERY IMPORTANT!!! Make sure you have the latest firmware in the scanner latest ver is 1.11.20

This latest version fixed the audio breaking up on most p25 systems!

Make sure you set the digital threshold mode to manual and play with the threshold level . My p25 system here works well with manual setting at 6.

Also turn off digital agc.

Tim
 

K3WSU

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BCD536HP Trunking audio distortion

Thanks to all for the replies...The only trouble is that to access the P25 adjustments, you have to be on a conventional channel/site. The ICORRS is a trunking site, APCO25.. and the menu selections for P25 adjustments are only under conventional system....the manual says it only applies to conventional sites, not trunking sites, or am I missing something...When I choose favorites editor, the P25 panes are "greyed' out and not accessible. The system type is defined as a P25 trunk. I'm confused..
 

mitbr

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Thanks to all for the replies...The only trouble is that to access the P25 adjustments, you have to be on a conventional channel/site. The ICORRS is a trunking site, APCO25.. and the menu selections for P25 adjustments are only under conventional system....the manual says it only applies to conventional sites, not trunking sites, or am I missing something...When I choose favorites editor, the P25 panes are "greyed' out and not accessible. The system type is defined as a P25 trunk. I'm confused..


It works on p25 trunking systems. Don't use sentinel. Go into the scanner menu select as follows
Press Menu then scroll to Manage Favorites and press E/yes.
Scroll to the Favorites List of the P25 system you want use and press E/yes.
Scroll to Review/Edit System and press E/yes.
Scroll to the System you want to edit and press E/yes.
Scroll to Edit Site and press E/yes.
Scroll to digital threshold mode
select manual
Scroll to digital threshold level select the level
press enter

There are 2 different digital adjustment settings one for non trunking and one for trunking. I showed you the way above to do this for trunking!
Also are you running the latest firmware?
Tim
 
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ofd8001

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While the fields appear to be grayed-out you can still click on them and make adjustments.

See photo
 
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K3WSU

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Hello Tim...THANKS !!! That is exactly what I was trying to do via Sentinel...now the display shows P25 mode of manual....somehow I missed that bit of info along the way...I have firmware Ver. 1.11.20 which I believe is the latest....thanks again for the information...
 

mitbr

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Hello Tim...THANKS !!! That is exactly what I was trying to do via Sentinel...now the display shows P25 mode of manual....somehow I missed that bit of info along the way...I have firmware Ver. 1.11.20 which I believe is the latest....thanks again for the information...

Your very welcome!! Please let us know if any manual settings work to improve your audio.

On my p25 system here in Florida it made a 100 percent improvement when I set it to manual 6 YMMV.

Let us know!

Don't forget to monitor the error rate on the system each time you change the manual setting. You want the lowest error rate for best audio. The error rate can be seen by pushing function/volume.
Tim
 

K3WSU

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Hello Tim and all....Just an update....by changing the threshold level to 6 or 7 and leaving the P25 mode in manual, results in a marked improvement. But going back to P25 mode Auto, leaving the Threshold at 6 or 7, results in choppy audio. I thought that setting the Threshold level in manual, would result in the new starting point for the Auto mode. Apparently not, as it looks like the starting point is at 8, which is where we started, must be a default point for the Auto mode. But overall, it's a big improvement. One other bit of information, this area geographically, is considered to be rural. My location is approx. 10-15 air miles from the site. I have an outdoor discone antenna at 30 feet. I have noticed some intermittent audio distortion. By enabling Global attenuation helps somewhat. I may be experiencing some multi-path problems, but these types of issues can be remedied...Again, thanks to all.............
 

ofd8001

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I also find Manual to be a lot better than Auto. I suspect that when in Auto, the scanner is trying too hard to deal with the bit error rate and can't seem to settle in on something. Thus the continuing change actually worsens things.

Also 7 seems to be my magic number. However there are so many variables, what works good for one person in one place on one system, may change for someone else.
 

Bryce031

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P25 Phase II Distortion

I too am dealing with a distortion problem and have been 'fiddling' with the threshold manual setting and have landed on 6 or 7. I currently have a discone antenna setup on an elevated pole above the roofline of the house. I believe the freq range is simply too broad and scattered to handle the 'technicality' of the multicasting from multiple tower sites. I ordered a Yagi directional antenna this morning with a high gain...I'm hoping this will remedy the problem.

System being monitored: Gloucester County (NJ) Fire & EMS

**Input/Suggestions welcome!
 

Jimco

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Decoding of P25 on some systems is really bad with Uniden scanners. Adjusting the threshold level does sometimes help. Here's a much easier way to do it.

While scanning the system, press Select, Func, Select. ("Select" by pressing down on the rotary knob.) This will display the current P25 settings at the bottom of the screen. You can then modify the threshold level by holding Func and turning the rotary knob.

With that said, if you are monitoring a system that doesn't come in well on the Uniden scanner, you're likely to never get great results. The quality of P25 decoding is simply not good on some systems. I suffer the same issue on my local P25 system, and I'm purchasing a Unication G4 because of it.

Jim
 

scannerjunkie

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Their was A firmware update just released for the 436 and 536. It adressed p25 issues as well as dmr fixes. If you have not updated give it a try. My 436 sounds so much better now.
 

DeDawg

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The 1.11.31 firmware upgrade did not do a thing to improve the horrible audio I get. Easily get zero BER, but audio is usually harsh and over modulated sounding. Like something is being over driven. Darn near unbearable to listen to female voices from dispatch at this point. Thankfully the little 325 is not nearly so bad.
 

eorange

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I suffer the same issue on my local P25 system, and I'm purchasing a Unication G4 because of it.
Jim
You will not regret purchasing the G4. I suffered for years with unfixable LSM distortion on GRE and Uniden scanners. I tried paper clips, 800MHz beams, HDTV antennas, fruitless parameter adjustments...nothing helped, which deep down I knew.

Now with my G4, I get absolutely 100% perfect flawless decode all the time, every time, on every P25 system up here, without fail.
 

Bryce031

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Decoding of P25 on some systems is really bad with Uniden scanners. Adjusting the threshold level does sometimes help. Here's a much easier way to do it.

While scanning the system, press Select, Func, Select. ("Select" by pressing down on the rotary knob.) This will display the current P25 settings at the bottom of the screen. You can then modify the threshold level by holding Func and turning the rotary knob.

With that said, if you are monitoring a system that doesn't come in well on the Uniden scanner, you're likely to never get great results. The quality of P25 decoding is simply not good on some systems. I suffer the same issue on my local P25 system, and I'm purchasing a Unication G4 because of it.

Jim


I looked at the Unication G4 after reading your post. Those units seem pretty versatile. Are they truly a scanner and a pager all in one?
 
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